A virtual simulation of a city, connected to real infrastructure systems any time - with the help of such ”Digital Twins” authorities and emergency services could anticipate disaster situations and predict the consequences of decisions. Scientists from the Institute for the Protection of Terrestrial Infrastructures at the German Aerospace Center (DLR), in collaboration with emergenCITY, have looked at how digital twins could improve the resilience of urban infrastructures.

In the article recently published in the journal “Sustainability Analytics and Modeling” entitled “Improving the resilience of socio-technical urban critical infrastructures with digital twins: Challenges, concepts, and modeling”, the authors Tobias Gebhard, Jonathan Sattler, Jonas Gunkel, Marco Marquard and Andrea Tundis present their research findings on the topic.

“Up to now, urban digital twins have mainly been considered for urban planning, for example to create interactive 3D models,” Tobias Gebhard, DLR and emergenCITY scientist, explains. “We wanted to apply the idea of digital twins to critical infrastructures and crisis scenarios.”

Digital twin as a crystal ball that simulates what-if scenarios

Natural disasters, extreme weather and wars can destroy vital infrastructures such as power grids, water supply systems and transportation routes. An urban digital twin as defined by the authors as a virtual replica that is connected to the physical city in real time, could simulate what-if scenarios, for example to assist crisis management in making quick and grounded decisions. For this purpose, data is continuously measured, monitored and analyzed.

“It is crucial to consider the complex dependencies between the systems as well as the behaviour of the people who live in the city and interact with the infrastructures”, Tobias Gebhard says.

Modeling framework integrates dependencies and human behaviour

The researchers developed a modeling framework that represents infrastructure systems for electricity, water and transport including their interdependencies. This is because the influence the systems have on each other becomes particularly apparent during a disaster, for example the Ahr valley flood 2021, whereas this is hardly noticeable during normal operation. The researchers also speak of a chain of unforeseen events, so-called “cascading effects”.

The team also incorporated socio-technical dependencies, i.e. the influence of city residents, in the modeling process. For example, data collected by smart meters can provide information on how much electricity or water is currently being consumed by the residents of a city. Sensors in traffic networks could show how and where people are moving. Geographical data, for example on the location of schools, in turn provides information on the location of people at certain times. Finally, the scientists investigated how the resilience of critical infrastructures against different hazard scenarios can be assessed quantitatively on the basis of their modeling framework.

The paper on urban digital twins is the result of three years of research. The findings have already been incorporated into the development of a demonstrator: NEXUS is a real-time simulator that can represent critical infrastructures and their interdependencies in order to analyze the consequences of potential incidents comprehensively and interactively.

Video about the NEXUS simulator

Video about the Nexus simulator
The NEXUS simulator is being developed by the LOEWE center emergenCITY and the DLR Institute for the Protection of Terrestrial Infrastructures.

Publication

Tobias Gebhard, Bernhard J. Sattler, Jonas Gunkel, Marco Marquard, Andrea Tundis, Improving the resilience of socio-technical urban critical infrastructures with digital twins: Challenges, concepts, and modeling, Sustainability Analytics and Modeling, Volume 5, 2025, 100036, ISSN 2667-2596, https://doi.org.

Further information

Project urbanModel at the DLR Institute for the Protection of Terrestrial Infrastructures: www.dlr.de